Gang-saw mill.



No. 812,539. PATENTBD FEBIIS, 1906.

W. M. 'WILKIN.

GANG SAW MILL.

APPLICATION FILED OCT. 18. 1905.

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GANG SAW MILL.

APPLICATION FILED OUT. 18. 1905.

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W. M. WILKIN.

GANG SAW MILL. APPLICATION FILED 061. 18. 1905.

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.By/CYM? UNITED STATES PATENT orrr on.

GANG-SAW IVIILL.

Specification of Letters Patent.

Patented Feb. 13, 1906.

Application filed October 18, 1905. Serial No. 283.239.

To all whom it wuty concern.-

Be it known that I, WILLIAM M. WILKIN, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylva- .nia, have invented certain new and useful Improvements in Gang-Saw Mills; and I do hereby declare the following to be a full, clear, and eXact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, forming part of this specification. I

My invention relates to improvements in gang-saw mills, and has for its object the construction of a gang-saw mill having steamcylinders therein, the piston-rods of which are connected direct to the saw-sash, so that the mill can be driven by said steam-cylinders or by belts in the usual manner after disconnecting said cylinders, also in counterbalancing the saw-sash and piston mechanism in such a manner that the vibrationproduced by the rapid reciprocations thereof is reduced to the lowest possible minimum. These and other features of my invention are hereinafter set forth, and illustrated in the accompanying drawings, in which Figure 1 is an end view in elevation of my improved gang-saw mill with a part of the frame broken away. Fig. 2 is a front view in elevation of the same with parts thereof broken away. Fig. 3 is a view of a portion of the same, showing a form of the crank-shaft and cranks. Fig. 4 is a view of a portion of the same, being a section on the line ac a: in Fig. 3, more particularly showing the construction of the counterweight. Fig. 5 is a detail view of the crank-shaft and pitman and counterweight connections.

In the construction of a gang-saw mill embodying my improvements, A indicates the base of a mill-frame, and A, A and A the sides and top thereof, which are of usual con struction. Longitudinally upon the base A in suitable bearings B B, (see Figs. 2 and 3,) I mount a crank-shaft B, having opposing cranks or eccentrics therein. In the construction of this crank-shaft B, I preferably construct the crank or cranks I), which are connected to and operate the sash-pitman b, of greater length or throw than the crank or cranks b to which the counterweights, hereinafter described, are secured.

In the upper part of the mill-frame, upon the inner faces of the side frames A A, I provide suitable sash-guides a a, within which a saw-sash C C of ordinary construction operates. The upper and lower plates of this saw-sash have studs 0, upon which the sashslides c are mounted. (See Fig. 2.) The lower sash-plate C of this sash is connected with the longer cranks b on the crank-shaft B by means of pitmen b in the usual manner.

Upon chairs D D, Figs. 1 and 2, over the crank-shaft bearings B B, I mount steamcylinders E E having therein the usual pistons (not shown) and the usual steam-chests and valve mechanism (not shown) and valvestems e for operating said valves. The upper ends of the piston-rods E are preferably connected rigidly to the lower sash-slides 0 0 so that as the pistonrods reciprocate up and down they compel a like reciprocation of the saw-sash C C, which through the pitman 1) causes the crank-shaft B to rotate. Upon the crank-shaft B, I mount an eccentric F, which has mounted upon it the usual collar N. (See Figs. 1 and 2.) To operatively connect this eccentric F and collar F with the valvestems e at each side of the mill, I mount a rock-shaft G in the side frames A A, as shown in Figs. 1 and 2, and mount thereon a lever G, which is connected to the eccentriccollar F by the eccentric-rod g in the usual manner. The rock-shaft G has also mounted thereon adjacent to the valve-stems e of the steam-cvlinders E valve-operating levers g, one for each valve, which levers are connected to the valve-stems e e in the usual manner, From this it is obvious that the valve mechanism for each steam-cylinder will.

be operated in unison by the eccentric F on the crank-shaft B.

In order to perfectly counterbalance the saw-sash and piston mechanism connected therewith, I have, as hereinbefore stated, constructed the crank-shaft B with the sash-cranks l) of greater throw than the counterweight-cranks 6 Upon this crank b of the crank-shaft B, I secure in a suitable manner the arm H of a counterweight H, or, more properly, the counterweight H is attached direct to the crank b in view of the construction thereof hereinafter described. Now as the crank b is of less throw than the sash-cranks b I preferably make the coun terweight H of greater weight than the weight of the parts it is desired to counterbalance. This I find in actual practice produces the ideal condition as to vibration of the crank-shaft-viz., that it will not pound even when the j ournal-fastenings are entirely removed, whereas with the old way of making the counterweight-cranks, with the same throw and the weight the same as the parts to be counterbalanced, that condition was not possible. I

To further aid in relieving the vibration and jar incident to rapidly-reciprocating parts, I construct the counterweight H with the arm H rigidly secured to the weight. This may be accomplished in any well-known manner, the main point being that there shall be no opportunity for wear at the point of union between the arm H and the body of the weight H. The upper end of this weightarm H is provided with a suitable bearing to be mounted direct upon the wrist-pin of the crank b To prevent the weight H from swinging laterally, I pivot to it a link h, the opposite end of which is pivoted to a projection h on the base A of the mill-frame.

. the mill by belts in the ordinary manner.

herein described I have eliminated one such bearing from the line of shock, so that there is no loose joint between the weight H and the crank-shaft B.

I have shown herein two different forms of connecting the saw-sash, crankshaft, and counterweightviz., two pitmen between the crankshaft and saw-sash and one counterweight-crank, which construction is preferable when constructing a mill to be run by steam, as herein described, and one pitman between the sash and crank-shaft and two counterweight-cranks. I have also shown two forms of cranks for the counterweightsviz., cranks and eccentrics, (see Figs. 3, 4, and 5;) but in either case the throw of the counterweight-crank is less than the throw of.

the sash-cranks.

Upon the ends of the crank-shaft B outside of the mechanism hereinbefore described I mount a fiy-wheel or pulley or pulleys J, which serve as balance-wheels to prevent a dead-center when the mill is operated by the steam-cylinders E E, but which pulleys can be used as drivers when it is desired to drive In the latter case the piston-rods E are disconnected from the sash, and the eccentric-collar F and rod 9 are removed.

It will be observed that the arrangement of sire to secure by Letters Patent of the United States, is

1. In a gang-saw mill, the combination of. a mill-frame, a saw-sash mounted in the upper part thereof, a crank-shaft mounted in the base of the mill-frame,1a sash-operating crank in said shaft, a pitman connecting said crank with the saw-sash, a counterweightcrank in said shaft in opposition to the sashoperating crank and of less throw than the sashoperating crank, a counterweight of greater weight than the parts to be counterbalanced connected to said counterweightcrank, and a link connected to said counterweight and extending laterally therefrom to a bearing on the mill-frame, substantially as described.

2. The combination in a gang-saw mill of, a mill-frame, a saw-sash mounted in vertical guides in the upperportion of said mill-frame, a crank-shaft mounted in the base of said frame, cranks in said shaft having a throw equal to the traverse of said saw-sash, pitmen connecting said sash and said cranks, counterweight-cranks in said shaft opposite to and having a shorter throw than said sash-cranks, counterweights on said counterweight-cranks steam-cylinders mounted above the bearings of said crank-shaft, pistons in said cylinders, piston-rods connecting said pistons and said saw-sash, valves for operating said pistons, and valve-operating mechanism adapted to operate said valves in unison, substantially as described.

3. The combination in a gang-saw mill of, a mill-frame, a saw-sash mounted on slides in vertical ways in the upper portion of said frame, a crank-shaft mounted in suitable bearings in the base of said mill-frame, one or more cranks therein adapted to be connected to said sash, and one or more opposing cranks, of less throw than the sashcranks, adapted to operate counterweights, pitmen connecting said sash-cranks to said saw-sash, counterweights of greater weight than the parts to be balanced, rigid arms on said counterweights connecting them with the counterweight-cranks, and pulleys mounted on said crank-shaft, substantially as described.

4. The combination in a gang-saw mill, of i vertical ways, a crank-shaftmounted in the base of said frame, one or more cranks in said crank-shaft having a throw equal to the traverse of the saw-sash, and one or more cranks therein opposite to and of less throw than said sash-cranks, counterweights of greater weight than the parts to be counterbalanced secured to said counterweight-cranks by means of rigid arms, links pivoted to said counterweights and to bearings on' the millframe, steam-cylinders mounted upon supports over the bearings of said crank-shaft, pistons in said cylinders, piston-rods connecting said pistons directly to said saw-sash, valves on said steam-cylinders for operating said pistons, stems connected to said valves, a rock-shaft mounted in said frame, levers on said rock-shaft connected to said valve-stems, a lever on said rock-shaft adapted to rock said shaft, an eccentric mounted on said crank-shaft, a collar embracing said eccentric, and an eccentric-rod connecting said collar and rock-shaft-operating lever, substantially as described.

5. In a gang-saw mill, a mill-frame, a sawsash mounted in the upper part thereof, a crank-shaft mounted in the base of the millframe, sash-operating cranks in said shaft, pitmen connecting said cranks with the sawsash, a counterweight-crank in said shaft in opposition to the sash-operating cranks, a counterweight, a rigid arm on said counterweight connecting it with the counterweightcrank, and a link pivoted to said counterweight and extending laterally therefrom to a bearing on the mill-frame, substantially as described.

In testimony whereof I affiX my signature in presence of two witnesses.

WILLIAM M. WILKIN.

Witnesses W. S. CARROLL, W. P. GIFFoRD. 

